The invention relates to a fastening system and a method for fastening an object in the form of a stake or post projecting from a surface, with an anchoring portion which can be introduced into an underlying structure bounded by the surface and can be removed again from it, or can be releasably fastened on the surface, and with a holding portion for receiving the object.
The erection of masts, posts, poles or stakes, for example for signs or fences, usually takes place directly by ramming them into the earth or by means of a foundation introduced into the earth for this purpose. With this procedure, the required vertical alignment entails considerable expenditure and requires the use of additional aids, which is laborious and, in particular, time-consuming. If it is concreted in, alignment of the object is no longer possible at all once the concrete has set.
In many cases, a mast or the like is not to be erected permanently but only for a time, for instance depending on the season, for example warning signs for hazards in winter or posts for setting up nets for ball games and the like. With the usual fastening methods mentioned above, a releasable connection is either not possible at all or requires additional measures.
In addition to ramming in, burying or concreting in an object, it is known to erect an object by means of a fastening system anchored in the earth. The anchoring device, which can receive the object to be erected at its upper, free end, includes at its lower end for example a screw or auger, which is screwed into the earth like a screw. The object to be erected is then inserted or screwed into the anchoring device or is screwed onto it. In the case of such arrangement as well, similar difficulties with regard to the use of additional aids exist regarding the alignment of the anchoring device in relation to the vertical and, in particular, when releasing the connection, and time-consuming additional measures are required.
The invention is based on the problem of providing a device and a method for fastening an object in the form of a stake or post projecting from a surface, in particular from the ground, with an anchoring portion which can be introduced into the underlying structure and can be removed again from it, or can be releasably fastened on the surface, and with a holding portion for receiving the object, with which device or method the object to be fastened can be aligned simply and in a short time and which permit sufficiently durable fixing of the object, even over prolonged periods, as well as comparatively quick and easily performed removal of the object.
The problem is solved according to the invention by a fastening system for an object in the form of a stake or post which includes a filler portion.
It is provided according to the invention that the holding portion has a cup-shaped or tubular filling portion, provided with a filling opening, for receiving a filler. The fastening system according to the invention therefore allows quick, easy-to-perform and exact alignment and positioning of the object in the form of a stake or post in relation to the holding portion, creating a durable fixing which needs no readjustment and can be easily released again. The components in the form of stakes or posts to be fastened may be variously designed, i.e. both cylindrical and conical components can be securely fixed, the conicity of the component also being formed in a frustoconical widening of the lower region of the component and/or in a conical tapering of the lower region of the component, thereby forming a relatively narrow annular gap. The system according to the invention and the method according to the invention can consequently be used for the secure fixing of a large number of components in the form of stakes or posts.
According to the invention, the filler is of such a nature that movement of the object in the holding portion is virtually ruled out. For this purpose, the filler expediently comprises a hard material in the form of sand, loose chippings or rock and/or a flexible plastic, such as granular material in particular. The invention is based on the surprising effect that filler which is, in itself, loose and to a certain extent xe2x80x9cfree-flowingxe2x80x9d indeed permits a fastening of the object that is mechanically adequately stable, without the effect of the mechanical connection subsiding over time. In this case, on the one hand easy-to-perform corrections in the alignment of the object are possible, and on the other hand simple release of the connection is made possible by removing or taking out the filler. Tests with coarse-grained, hard loose chippings, as are used in road construction for example, have shown that secure fixing is possible just by the force of gravity of the filler introduced and the mechanical pressure of the filler acting on the object. After introducing the filler, the object is securely held, even under the effect of external vibrations, and does not exhibit any, or in any event any appreciable, positional changes. The coarse-grained material of the filler assumes a physically stable, essentially unchanging position after filling and securely holds the object. Not only coarse-grained rubble is possible for the material of the filler, although such a material appears to be particularly well suited (since canting of such a material achieves particularly great rigidity and positional stability of the filler, which is retained even under relatively great loading), but also rounded or even spherical rock material, such as pebble stones or the like, for instance.
A further aspect of the present invention is therefore that of providing filling material for the fastening of objects in the form of stakes or posts which has a rough, irregularly formed surface. With such irregular, but nevertheless approximately equal-sized filling-material elements, the advantageous effect of the device according to the invention is brought out particularly distinctly.
An additional aspect of the present invention is to fill the annular gap between the component in the form of a stake or post and the anchoring device only with individual particles or elements of the filling material in order to mount the component in the form of a stake or post in a secure and stable manner. This utilizes the effect that even just a few, but at least two, particles or elements of the filling material are sufficient in the relatively narrow annular gap between the component in the form of a stake or post and the anchoring device to bring about an adequate wedging effect to mount the component in the form of a stake or post securely and stably, in particular with respect to vertical forces. It must be ensured here that the annular gap is not greater than the diameter of the particles or elements of the filling material. It has therefore proven to be advantageous if the base region of the anchoring device has a cone in which the component in the form of a stake or post is centered and the annular gap enclosing the component in the form of a stake or post opens in the upward direction.
Also particularly suitable is a flexible plastics material, for instance a coarse- or fine-grained granular material, which can be produced in particular from recycled materials, for instance from scrap rubber (scrap tires) or other suitable reusable plastic waste products. One special advantage of using a flexible filling material exclusively or in addition to other material, apart from an improved fastening effect that is more stable on a long-term basis, is in particular the vibration-damping and stress-retaining properties of such flexible filling material.
The filler is preferably filled into the filling opening by means of a funnel-like filling tube that reaches at least partly around the circumference of the filling opening.
A major advantage of the invention is that there is simple and accurate positioning of the object to be fastened. Not only can the axial position of the object be easily set, but any desired position of the object within the holding portion can also be accomplished. In this way, it is readily possible with extremely simple handling still to accomplish a desired position or directional correction of the object to be fastened even when the holding portion is fitted at a slant or in a position deviating from the actual desired position.
It is favorable if the filling material is adequately coarse in comparison with the outer dimensions of the object, i.e. the outside diameter in the case of a cylindrical object, from approximately one to at least a few millimeters or even a few tens of millimeters. But even comparatively fine-grained sand with a grain size below one millimeter exhibits in principle the required mechanical strengths and is therefore similarly suitable for the purposes according to the invention; however, it is to be ensured by additional means that the filled small-grained sand material cannot escape. Expedient particularly for this eventuality is a closing material which completely closes the filling opening and with which a mechanical pressure is at the same time also exerted on the sand material for compacting it.
With adequately coarse-grained material, on the other hand, it is not necessarily required for the filling opening to be completely covered to achieve the connecting effect according to the invention, since such a filler normally achieves adequately high rigidity by itself and also remains positionally stable with respect to vibrations or weathering effects or other external loads. Nevertheless, a closing means that covers the filling opening of the filling portion at least in certain regions and is releasably fastened at the edge region of the filling portion may be expediently provided for increasing the strength of the connection.
According to a preferred development of the fastening system according to the invention, the cup-shaped or tubular filling portion for receiving the filler is formed by an insert which can be inserted into the holding portion of the anchoring device and removed again. Accordingly, the insert is preferably formed by a prefabricated part of plastic or sheet metal. The insert may additionally also be formed by a bag made of a film of flexible plastic or else made of woven material and expediently provided with a bottom reinforcement withstanding the weight of the object. Such an insert makes it possible in an extremely simple way for the filler to be taken out again from the filling portion after removal of the object. Dismantling of the fastening device, but also renewed fixing of an object in the form of a stake or post, is consequently easily and quickly possible.
The method according to the invention for fastening an object in the form of a stake or post projecting from a surface in the underlying structure or on the surface by means of a fastening system which has an anchoring portion which can be inserted into the underlying structure and removed again from it, or can be releasably fastened on the surface, and a holding portion for receiving the object, is distinguished by the following steps:
introducing the anchoring portion of the fastening system into the underlying structure or arranging the anchoring portion on the surface;
introducing, aligning and positioning the object in the holding portion of the anchoring device;
filling a filler into a filling portion, provided with a filling opening, of the cup-shaped or tubular holding portion, thereby securing the aligned position of the object; and, if appropriate
durable fixing of the object by covering the filling opening by a closing means which covers the filling opening of the filling portion at least in certain regions and is releasably fastened at the edge region of the filling portion.
According to a preferred development of the method, it may be provided that the filler is permanently subjected to mechanical pressure or compressed by a clamping means. This method step is preferred in particular in the case of an angular filling material, and in turn in particular in the case of an angular hard material in the form of sand, loose chippings or rock, in order to counteract a reduction in the fastening effect caused over the course of time by vibrations or other mechanical effects of the object.
A further preferred method according to the invention consists in that coverage of the filling opening by closing means is not necessary for durable fixing of the object in the form of a stake or post, since the filler remains securely in the optionally usable insert or directly in the receiving region of the anchoring portion on account of its gravity, its blocking function and the static friction between the respective elements of the filler.
When a round or approximately round filling material is used, it is preferred in a development of the invention if the filling opening of the filling portion is covered by the closing means, in order that the filling material cannot escape from the filling portion, and at least a certain initial pressure is applied to the filler by the clamping means.
In a particularly preferred development of the invention, it is provided that the fastening system or its anchoring portion is screwed or knocked into the earth.
Furthermore, for use of the fastening system, objects in the form of stakes or posts which are designed essentially in a frustoconical form on their lower side may be used. Such a frustoconical surface at the lower end of the object in the form of a stake or post makes it possible for the objects in the form of posts to be fixed in a load-bearing and reliable way. This utilizes in particular the clamping mechanism of the filler, it not being important for an insert to be fitted in the actual receiving element of the anchoring portion. To achieve the necessary holding effect of the object in the form of a stake or post, it is sufficient for only an opening that is essentially triangular in section to be formed as an annular gap between the lower end of the object in the form of a stake or post and the holding portion. As soon as such a sectionally triangular annular gap has been formed and filler has been introduced into this intermediate space, the particularly advantageous wedging effect is brought about, permitting reliable and secure fixing of the object in the form of a stake or post according to the invention. A major advantage of the fastening system in connection with the component in the form of a stake or post to be fastened is that, with conically designed receiving elements of the anchoring portion, adaptation of the diameter of the object in the form of a stake or post, with for example a cylindrical inserting portion, is not required. The cone angle, i.e. the included angle of the triangular annular gap, has a magnitude of greater than 0xc2x0 and less than 45xc2x0, preferably 3xc2x0 to 15xc2x0.
A further aspect of the fastening system according to the invention is a dome-like compensating means which is arranged at the bottom of the insert in order to create a secure and stable supporting surface in the case of slanting components in the form of stakes or posts, which preferably include a tube. For this purpose, the dome-like compensating means is preferably a spherical cap which is either everted upward into the insert or formed downward as a depression. The dome-like compensating means is at the same time dimensioned in such a way that the annular supporting region of the component in the form of a stake or post rests with its entire circumference on it. The dome-like compensating means can be introduced as a removable component according to requirements into the bottom region of the insert, if the component in the form of a stake or post cannot be aligned coaxially with the anchoring device. In this case, the dome-like compensating means forms the supporting surface for the hollow component in the form of a stake or post, in order that filler does not get under the supporting edge of the component and in order that the latter does not consequently slip away on the planar base of the insert on account of being supported by its edge on one side.
An additional aspect of the present fastening system is that of providing centering means which center the components in the form of stakes or posts in their position in relation to the vertical. The centering means may in this case comprise the conical inner region of the anchoring device or attachable centering means, for example in the form of disks, which can preferably be arranged on the upper side of the insert radially with respect to the component in the form of a stake or post. It is optionally also possible for both centering means to be used, i.e. centering in the conical bottom region and centering by means of disks.
The fastening system according to the invention can consequently be constructed in a modular manner according to requirements from a plurality of component parts. The individual component parts of these fastening systems comprise:
an anchoring device, for example a bottom plug, knocking-in sleeve or mounting stand;
an insert for inserting into the anchoring device, optionally cylindrical or conical, optionally with a centering function in the lower or upper region of the insert;
individual filler particles for fixing the components;
a multiplicity of filler particles for filling up the insert or the anchoring device;
centering means for centering the components in the form of stakes or posts at the upper region of the anchoring device;
centering means for centering the components in the form of stakes or posts at the lower region of the anchoring device;
closing means without a centering function, with which the filler is subjected to mechanical stress;
a dome-like compensating means for slanting anchoring devices or components to be erected at a slant.
On the basis of these modular components, different exemplary embodiments of the fastening system according to the invention can be formed, the following list giving some but not all exemplary embodiments of the possible combinations of the modular fastening system.
Example 1: fastening system comprising an anchoring device with a conical inside wall, into which the component in the form of a stake or post is inserted and with which the space between the component in the form of a stake or post and the anchoring device is filled by means of a multiplicity of filler particles.
Example 2: fastening system comprising an anchoring device into which there is fitted an insert with a conical inside wall, into which the component in the form of a stake or post is inserted, and the space between the component in the form of a stake or post and the insert is filled by means of a multiplicity of filler particles.
Example 3: fastening system comprising an anchoring device into which there is fitted an insert with a cylindrical inside wall, into which the component in the form of a stake or post is inserted, and the space between the component in the form of a stake or post and the anchoring device is filled by means of a multiplicity of filler particles.
Example 4: fastening system comprising an anchoring device with a cylindrical inside wall, into which there is fitted an insert with a conical inside wall, into which the component in the form of a stake or post is inserted, and the space between the component in the form of a stake or post and the anchoring device is filled by means of a multiplicity of filler particles.
Example 5: fastening system comprising an anchoring device with a conical inside wall, into which the component in the form of a stake or post is inserted and centered by centering means at the end of the component, and the space between the component in the form of a stake or post and the anchoring device is filled by means of individual filler particles in such a way that these filler particles exert a clamping effect, in particular in response to vertical forces.
Example 6: fastening system comprising anchoring device with a conical inside wall, into which the component in the form of a stake or post is inserted and centered by centering means at the upper region of the anchoring device.
Example 7: fastening system comprising an anchoring device with a conical inside wall, into which the component in the form of a stake or post is inserted and centered by centering means at the upper region of the anchoring device, and with which the space between the component in the form of a stake or post and the anchoring device is filled by means of individual filler particles in such a way that these filler particles exert a clamping effect, in particular in response to vertical forces.
Example 8: fastening system comprising an anchoring device with a conical inside wall, into which the component in the form of a stake or post is inserted and centered by centering means at the upper region of the anchoring device and at the end of the component, and in which the space between the component in the form of a stake or post and the anchoring device is filled by means of individual filler particles in such a way that these filler particles exert a clamping effect, in particular in response to vertical forces.
Example 9: fastening system comprising an anchoring device and an insert, into which the component in the form of a stake or post is inserted and centered by centering means at the bottom of the insert and the space between the component in the form of a stake or post and the insert is filled by means of individual filler particles in such a way that these filler particles exert a clamping effect in response to vertical forces.
Example 10: fastening system comprising an anchoring device and an insert, into which the component in the form of a stake or post is inserted and centered by centering means at the bottom and at the upper region of the insert.